Method of drawing glass.



R. L.- FRINK METHOD OF DRAWING'GLASS.

APPLICATION IIi-ED JUNE 22, 1908. I 1, 1 1 9,00 Patented Dec. 1, 1914.

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UNITED STATESPATENT OFFICE.

ROBERT L. FRINK, 0F CLEVELAND, OHIO.

METHOD OF DRAWING GLASS.

To all whom it may) concern:

Be it known that I, ROBERT'L. FRINK citizen of the United States, resident of Cleveland, county of Cuyahoga, and State of Ohio, have invented a new and useful Improvement in Methods of Drawing Glass, of which the following is a specification, the principle of the invention being herein explained and the best mode in whichl have contemplated applying that principle, so as todistinguish it. from other inventions.

The present invention, pertaining to the artpfdrawing glass andparticularlv to that of drawing glass cylinders, or rollers, has as its object the provision of a method and apparatus suitable for use therein whereby such drawing maybe considerably facilitated and the satisfactory character of theproduct better assured than in prevailin: typesof apparatus. v

The general mode of drawingenemplified in the present improvement is the same as that of United States Patent, N 846,102, issued tome March 15, 1907, and consists broadly in providing a drawing pot or vessel with a continuous supply of glass drawin: therefrom a continuous cylinder orother hollow article and severing the same into I lengths as it is drawn Inthe case of such patented method and apparatus the drawing is accomplished by progressively changing the point of application of the drawing strain tothe. cylinder airmbeing supplied to 'th e. interior, of; the cylinder at its lower end and below the point where .the glass sets, and the action of such air-upon the article being utilized to control its escape. However, as will appear, this particular drawing mechanism is. to he considered as merely illustrative, sinceit is rather with the supplying of the molten glass to such mechanism, whatever the character of the latter, that we here have concern.

The object of the invention. then, is the provision of means for controlling the supply of molten glass to the drawing pot where such supply is had direct from the furnace or equivalent source in more or less continuous fashion.

To the accomplishmentof this and related objects said invention consists of the means hereinafter fullydescribed and particularly pointed out in the claim.

The atmexeddrawings and the following description set forth indetai-l certain steps embodying the 'invention, such disclosed Specification of Letters Patent.

A pl es-a filed June'22, 1908. Serial No. 439,767.

Patented Dec, 1, 1914.

' steps constituting, however, butone of various ways in which the principle of the invention may be used.

In said annexed drawings: Figure 1 is a vertical section through one approved anrangement of apparatus adapted to the carrying out of my improved method of draw-- i-ng glass the section being taken on the line 1 of Fig. 2; Fig. 2 is a transverse section of such apparatus taken; on the line 22, Fig. 1, and Fig. 3 is a vertical section,

taken on the line 3'3 of Fig. 2.

In such drawings, there is shown a glass melting furnace A of any suitable character provided with anexten'sion or dog-house a, with which the drawing pot B is designed to be connected. Communication is had betweentlie extension 6 and such pot through a passage or conduit A as shown, a gate af being interposed between such passage and the extension By operation of which the flow of molten glasirito the drawing pot or vessel B may bestopped when desired. The drawing mechanism proper comprises a set of rolls D, between which the cylinder C is pressedaind drawn. upwardly, once it has been started, and an air regulating head B that extends upwardly through an opening intheghottom of the pot 0: ashort distance above thecontemplated-level of molten glass therein. Th:0peratioii of suchdrawing mechanism"'needj'not lbe further: noted in this connection than to state that the air, which is suppliedto the head through a pipe is dischar jed intotthe lower por tion of the cylin er being rawn', from whence it escapes around such head by distendingv the cylind r wallsagreaten orless deglfifi as is fully described in the aforesaid Letters Patent, No. 846,102. In such patent of reference, as also in connection with apparatus for drawing glass theretoforemseli, it has been contemplated that theglass in the drawing pot or receptacle should be maintained at the proper drawing temperature by means of auxiliary burners and in certain methods it has furthermore been attempted to thus artificially control the temperature of the glass in the pot by theuse of cooling means as well. the latter being located contiguously to the point from which the cylinder rises from the molten bath. As explained at some length in a co-pending application filed September 25,

1907, Serial No. 394,459, I am convinced as a result of numerous experiments that such attempted regulation may well be dispensed with in both instances. since in practice the harmful effects accruing therefrom far outweigh any alleged theoretical advantages. In other words no heating means have been found susceptible of such exact andnice control as not to exercise a greater heating effect on the cylinder at one'point than at another; while similarly the cooling effect of a water coil encircling the cylinder will obviously vary at different points in its circuit, producing cords and other inequalities in the cylinder. I accordingly should propose to eliminate for the most part slfch external heating and cooling means, thus leaving as the only element to be dealt with, that of conduction.

Laying aside the proper insulation of the drawing pot to prevent unequal radiation of heat therefrom, the problem of securing uniform surface tension at all points in the circle, from which the rising cylinder springs, resolves itself into so regulating and .directing the supplyof fresh molten glass to said drawing pot as to subject such metal to uniform temperature changes from the point at which itis admitted to the pot until it reaches the circle aforesaid. By the present apparatus I propose to'accomplish this byproviding the lateral inlet or opening 6 in the drawing receptacle with an over-arching projection b so disposed as to conduct the metal flowing in from the conduit to substantially the lower central portion of the pot, the location of the pointof discharge being such that, in rising todifferentpoints in the circle defining the cylinders base, the metal will have cooled a substantially uniform amount. To. this end I esteem it desirable thatthe point of discharge in question should not only lie Within the prolongation of the cylinder walls, but should be at a depth from the surface greater than the radial distance to such wall, 2'. e. greater than the radius of the cylinder.

Copies of this patent may be obtained for By means of the foregoing improvements in the construction of the drawing pot, the drawing of glass cylinders of indefinite length is rendered wholly feasible, the molten glass in such pot being maintained in a state more uniformly consistent than is possible even where the method of ladling is employed and only a limited quantity of metal presented to the drawing mechanism. The over-arching of the inlet opening in the pat corrects the natural tendency of the hotter inflowing metal to rise directly to the surface, thus causing the temperature on the one side of the head B ,to be too high for drawing while on the other side the glass is congealing. By my method on the contrary,

the fresh metal is caused to diffuse gener-.

ally throughout the mixture in the pot and the temperature of the upper stratum, from which the drawing takes place, is left un disturbed.

Other modes of applying the principle of myinvention may be employed instead of the one explained, change being made as regards the steps herein disclosed. provided the steps statedv by the following claim or theequivalent of such stated steps be em:

ployed.

I therefore particularly point out tinctly claim as my invention The method of producing. hollow glass and disarticles,- which consists in drawing a continuous cylinder from a bath of molten glass, and simultaneously replenishing such bath by supplying fresh molten glass there'- to at a point directly below and wholly within the radius of said cylinder, at a depth from the surface of the bath atleast equal to the radius of the cylinder and substantially central with respect to the cylindrical wall.

Signed by me this 16th day of June, 1908.

ROBERT L. FRINK. Attested by-.-

' E. R. Rom),

JNo. F. OBERLIN.

five cents each, by addressing the "Commissioner of l'atents,

Washington, D. 0, 

